1. Field of the Invention
Exemplary embodiments of the present invention relate to a communication system, and more particularly, to an apparatus and a method for normally receiving data by accurately estimating and compensating for a frequency offset for a wireless frequency channel through which data are transmitted in a communication system under wireless frequency environment.
2. Description of Related Art
Research into plans for providing services of various qualities of service (QoS) having a high-speed transmission speed to users in a current communication system and research into schemes for stably transmitting large-capacity data through limited resources at high speed have been actively conducted. In particular, research into data transmission through a wireless frequency channel has been progressed in a communication system. Recently, schemes for transmitting and receiving large-capacity data using effectively using the wireless frequency channel have been proposed.
Meanwhile, data are transmitted and received using a frequency division multiple access scheme so as to transmit and receive large-capacity data through the wireless frequency channel in the communication system. In this case, the frequency offset for the wireless frequency channel is generated. The generated frequency offset degrades performance of data transmission and reception of the communication system and therefore, the accurate estimation and compensation of the frequency offset are required so as to improve the performance of data transmission and reception. In order to estimate and compensate for the frequency offset, various schemes have been proposed. As an example, the schemes for estimating and compensating for the frequency offset using a cyclic prefix (CP) (hereinafter, referred to as ‘CF’), preamble, and the like, have been proposed.
However, the schemes for estimating and compensating for the currently proposed frequency offset, in particular, the schemes for estimating and compensating for the frequency offset using the foregoing CP or preamble increase a length of a training symbol corresponding to the CP or the preamble on a time base so as to more accurately estimate the frequency offset. As the length of the training symbol is increased, the data capacity that is transmitted and received through the real wireless frequency channel is reduced. Further, in order to transmit and receive the large-capacity data through the wireless frequency channel, the length of the foregoing training symbol is reduced. As the length of the training symbol is reduced, there is a limitation in accurately estimating the frequency offset.
Therefore, when transmitting and receiving the large-capacity data through the wireless frequency channel in the communication system, a need exists for schemes for improving the performance of the data transmission and reception of the communication system and normally receiving the large-capacity data through the wireless frequency channel, by accurately estimating the frequency offset and then, compensating for the estimated frequency offset.